That gun would be what collectors call the .38 Double Action Fifth Model. The .38 Double Action was introduced in 1880, but the Fifth Model was made from 1909 to 1911. As you can judge by the large quantity made, the .38 DA is quite common and is in demand by collectors only if in excellent condition. Value can range from $100 to as high as $500+, but the latter figure would only apply if the gun is like new and in the original box. Many show hard use and nickel plated ones usually show signs of peeling.
As a shooter, it uses the .38 S&W cartridge, which is less powerful than the .38 Special. Some consider it borderline for defense, but it was used for many years as a police cartridge. Be warned, though, that few parts are available for the gun if anything breaks.
Jim
